1. Field of the Invention
The present invention relates in general to a method of molding a skin-covered foamed plastic article, and more particularly, to a method of molding the foamed article which has certain portions which are different in resiliency.
2. Description of the Prior Art
Hitherto, in the field of seat manufacturing, a so-called "skin-covered foamed plastic pad" has been commonly used as a cushion member of a seat cushion part and/or a seatback part.
One of conventional methods of producing such pad is as follows.
An outer skin member is put into a cavity of a lower mold having a peripheral portion thereof seated on the edge of the cavity of the mold, and then an upper mold is put on the lower mold in a manner to pinch the peripheral portion of the skin member. Then, a foamable liquid material is poured into a bag-shaped outer skin member in the mold and cured in a suitable manner. After the material is hardened to a sufficient degree, the upper mold is removed from the lower mold and a product, viz., the skin-covered foamed plastic article, is took out from the lower mold.
In the seats, particularly the seats for automobiles, it is sometimes required that some portions of the seat have different but desired resiliency for the purpose of providing a seat occupant with a comfortable sitting feeling.
For example, the pad for a buckle type seat is constructed to have a major portion on which the weight of a seat occupant is directly applied and two raised side portions which are arranged at sides of the major portion to stably hold the body of the seat occupant. In fact, the major portion is constructed relatively soft for reliably bearing the weight of the seat occupant, while, the two side portions are constructed relatively hard for obtaining a desired occupant holding performance.
However, in the conventional method as described hereinabove, the production of the relatively hard side portions of the pad has been made by putting foreign things, such as rubber chips or the like, into certain portions of the cavity of the lower mold before pouring the material into the cavity. Furthermore, the resiliency of the side support portions of the pad has been adjusted by controlling the forces of springs which support the side portions. As is known, these steps are difficult or at least troublesome.